Improvement in the manufacture of chronometer-balances



1.- B. GOODING.

Manufacture of Chrunnmeter-Balances.

No.\57,3l9. Patenred'nec.1,1a74.

Fiy- 7.

UNITED STATES PATENT GEEIoE.

JAMES B. GOCDING, CF WALTHAM, MASSACHUSETTS.

IMPROVEMENT IN THE MANUFACTURE OF CHRONOMETER-BALANCES.

Specification forming part of Letters Patent No. l 57,319, dated December 1, 1874; application filed October 22, 1874.

, in the accompanying drawings, of which- Figure l denotes a top view, and Fig. 2 a transverse section, of the parts of a compensation-balance, as formed and prepared for ,being subjected to the action of a furnace.

Fig. 3 is a transverse section, and Fig. 4 a top view, of the steel blank and the brass tireholder or capsule.

Compensation balances for chronometers and tine time-keepers are usually made with a steel body and an encompassing ring of brass united together, the two metals having differ- Aent degrees of expansion under any change of temperature. The brass has to be fused and welded tothe steel. As usually accomplished, there is great danger ot' overheating the steel, particularly when the steel blank has a circular groove arranged concentrically in it and the brass melted into such groove. In this latter case the part outside of the brass or its groove, being usually narrow, is very liable to get overheated, so as to become brittle and too hard to work.

In carrying out my invent-ion I make use of a flanged capsule or ring, A, the flange a ot' which is extended inward from the lower edge ot' the ring, and is recessed or rabbeted conl centrically, as shown at b, to receive the circular disk B of steel, and hold it concentrically with the said ring, there being between the inner circumference of the ring and the periphery of the disk an annular space for reception of a brass ring or envelope, C, which is to till the space and rest on the ange a.

'lhe said flanged rin g-holder or capsule A I make of brass having a greater proportion of copper than the brass composing the ring C, in order that it shall not melt at the temperature at which the ring C would melt, but require a higher temperature to melt. I also form the capsule A of a metal or composition of metals such as will melt at a temperature below that at which the steel blank will bear without injury, the object being to prevent the said blank from being overheated in the furnace.

Having arranged the capsule, the steel blank, and the brass ring togetherin manner as shown in Figsland 2, and putupon the ring a proper quantity of iuX, l introduce the whole into a furnace, and there subject the three to a temperature sufficient to melt the brass ring and cause it to weld or braze to the blank and the capsule.

While the capsule may remain intact'the blank will not be overheated; but in case of the temperature being too high, or sufficient to damage the blank, the capsule and brass ring will be melted down. Thus, so long as the capsule may remain entire, We have evidence that the blank has not been overheated.

I claim- As an improvement in the art of manufac-V JAMES B. GOODING. Witnesses:

It. H. EDDY, J. R. SNOW. 

